This invention concerns a belt drive for transmitting power between machine elements by means of a drive sheave carried on one element and a driven sheave carried on a second element and a belt trained around them and, more particularly, a means for controlling belt tension according to drive loading.
Simple belt tensioning arrangements using center distance adjustment or adjustment of an idler pulley against a run of the belt are well known. Typically, such devices produce an approximately constant tensioning force which must of course be adequate for the maximum load to be imposed on the drive. Thus, at partial load conditions, the drive system is subjected to unnecessarily high belt tension which may shorten the life of its components, such as the bearings of the driver and driven sheaves and of the belt itself.